Headlights + Elec Fan = Horrible Idle

[Katapl]

So you pretty much get the idea. I've been struggling with this problem for months now, and I can't even drive around at night. Unless I like listening to a violent shaking in the engine bay. Anytime anything which draws power is turned on, the idle decreases more and more. With the headlights on, fan on, and myself stepping on the brake, it must get right to the point of almost dying. It shakes so hard and drops around 600 rpms.

I just cleaned up every 2 ground wires and added a 3rd, and the problem still remains. The IACV plug and socket was corroded, so I cleaned it up to look almost new. The problem is still around. The alternator, yup... it tests perfect.

Any ideas before I flip-out and just part it all out?

[biosehnsucht]

battery terminals?

belt adjustment?

how was the alt tested? did you get any actual results or just 'pass/fail' ?

have you tried replacing the battery? what sort is it ?

[Katapl]

The battery terminals are brand new. They came with my relocation kit (I had problems prior to relocation too).

The belt is in great shape and is on somewhat tight. Myself and my father both agreed the belt was perfect.

I don't quite know 'how' the alt was tested. It simply passed at autozone, and the rebuilder only said it was putting out what it was supposed to. Autozone told me their machine puts a load on it, so you would imagine it wouldn't pass with too much load, but that wasn't the case.

The battery is new. My father brought it home from Autozone about a week or so ago. It's just one of those standard car batteries that everyone uses. I'd say it weighs about 30'ish lbs.

I'm really at a loss for ideas here.

[boost_boy]

You are having charging issues, my friend. When you relocated your battery, did you properly ground the ground wire? Did you purchase a fuse block to properly feed the two wires that were once attached to the stock battery terminal? If you didn't wire the car back up the way it is supposed to be wired, you are going to have the issues that you are having.

Dee

[Katapl]

The battery stays at around 14.12 volts with no accessories, and around 14.02 with everything on. I also thought it was the charging system, but the good voltage leads me to thing otherwise. On the relocation, the ground was done proper. I took a hand grinder and took the paint off the spare tire tiedown thingy and grounded it there.

I wasn't the one who wired the positive battery setup in the engine bay. From what I saw, a friend of family (who was basically helping out) had just took the terminals (was something like 3 total) and just put a screw through them and taped them up. Naturally, I thought it was pretty ghetto, but it seemed to work okay. I believe it had done this pre-relocation too.

I'm not sure how the fuse block is supposed to be setup in the front. I had saw that done on a write-up. Do you think my problem is way the positive setup is wired? How could I change it up? I don't particularly know much about wirings. Hence why I didn't even do that part.

[Katapl]

Okay.

3 of the cables go into what's probably a circuit breaker. I've never seen one like this, so I haven't any idea if it is one or not. The accessories, battery, and alternator wire go into the red plastic piece. I really haven't any clue exactly what it is. I hate, hate, hate electrical. The starter wire is bolted together on it with the battery cable wire.

I'll probably have pictures tomorrow, I hope.

[float_6969]

It's just there to connect those wires to the positive battery terminal, that's all.

Is the engine grounded to the chassis? There should be a large ground cable that runs from the intake manifold to under the battery tray.

If it was me, I'd start busting out a multimeter and and checking ohms of resistance on all of the grounds you can.

Also, is it possible, that your idle control valve has just simply failed and so when the motor is under a load, it doesn't idle up like it should? What happens when you turn the wheel with the motor running?

[Katapl]

Is the engine grounded to the chassis? There should be a large ground cable that runs from the intake manifold to under the battery tray.

so when the motor is under a load, it doesn't idle up like it should? What happens when you turn the wheel with the motor running?

The engine is grounded from the intake to the chassis and from the exhaust side head to the chassis (which I added tonight per suggestion).

Right. That's exactly what it does. When I turn on too many accessories, it just bogs down instead of holding a steady idle. The P/S isn't hooked up, so it doesn't do anything except simply turn the wheels.

I suppose the idle control valve could have died. That's the piece that's in the very front on the manifold, right? It has a hose in, plug connector, and hose out, right? The connection and plug from the harness of that valve were severely corroded. I did my best to clean them up, and I think I did okay. When I tried running it without plugging that in, it ran worse that ever and idled up to 4k on just start. I immediately plugged it back in. Could it really have possibly died?

[ca18detgabby]

WHAT WTF? 14.2? it is a 12 volt battery....... if it is superb it is 12.7ish........

you must be using a marine battery..... those are real hard on the alternator and like to pop things.

I would check out the inline fuse or w.e you want to call that on the alternator again. if they did an in engine bay test of your alternator then it probably read fine under load as the battery itself w/o the alternator should be able to feed most of it.........

however after alternator it is changed to 24V IIRC...... thus you maybe either over powering things or may infact be under powering things.......

I would spend another afternoon checking those ground again. all of the engine bay and the hatch.PS Ive been sold bad batteries before too, so god only knows when you buy a cheapo how amazing it is going to be.

[Bwana]

I would also consider the possibility that one or more of the accessories mentioned is pulling an inordinate amount of amperage...

[lostmenoggin]

Those are good numbers for a battery tested on a running car. The alternator keeps the numbers a little higher. 12-12.7 would be if the battery was tested out of the car. My car is usually around 13.8-14 running.

I have the same problem only not as bad. When my e-fans (FAL 220) kick on they draw a lot of power and my rpms fall off a little bit too. My battery is also relocated. I was wondering if there a way to wire them so idle bumps up when there is a large draw on the system.

[Katapl]

I would also consider the possibility that one or more of the accessories mentioned is pulling an inordinate amount of amperage...

Well, every accessory does this. It's not just a few. Opening a door so the auto seatbelt moves... small rpm drop. Turning on headlights... huge rpm drop. It just depends how much power each accessory uses.

And the 14.02 was tested with the vehicle running and all accessories on.

[biosehnsucht]

I suppose the idle control valve could have died. That's the piece that's in the very front on the manifold, right? It has a hose in, plug connector, and hose out, right? The connection and plug from the harness of that valve were severely corroded. I did my best to clean them up, and I think I did okay. When I tried running it without plugging that in, it ran worse that ever and idled up to 4k on just start. I immediately plugged it back in. Could it really have possibly died?

No, that's the cold start gizmo. It has a wax thing that closes up as it heats up from the power running through the heating thing in it.

The idle air controller is part of the little block on the side of the intake manifold. It has the idle set screw which just lets in a fixed amount of air, the actual IAC/IACV (whatever you want to call it ) idle control valve/thing that the ECU PWM's to maintain idle by letting in more air. and the FICD which just opens up more air when AC is on (it's on or off). FICD is the one that sticks out towards the motor and is often broken.

http://web2.impactblue.org/con...h=148

The 16250N peice in the middle there is the fitting they all bolt to and in turn bolts to the intake manifold, the 23781H is the idle set screw, 16252M is the FICD, 23781M is the IAC/IACV/etc.

The little block has an air inlet that is connected via a short hose to the bras pipe under the intake manifold which goes around to the front and is hosed to a T that also goes to the cold start thing, and to the intake pipe ahead of the throttle body.

[Katapl]

The very top of that unit is unplugged on my engine, and shows two prongs. Is that just for A/C or is it necessary for it to be connected?

This is NOT my engine, but here's a reference of what part is unplugged on mine...

[maik21]

my car has 14.4 volts with engine on.. and 14.2 with fans and lights on.

12.7 with engine off, its a full battery.

maybe u need to do a back step and reconect the battery in his original place and test the car again.

if before battery relocation car idles fine with lights and fans on, u have a wire problem.

ur case isnt a charge issue because ur voltaje its 14 volts.. big amount of amperaje isnt a issue because if it was, the voltaje will rise to 15-17 volts .

maybe u are taking ur fans energy from a bad point.

try disconect ur power fan wire and hook it directly to battery and check if problems still there.

[Katapl]

The fan is ran right off the positive wire where everything else meets in the engine bay. It's simply wired to switch in the car.

[Katapl]

I pulled the codes, and I initially missed the first set that were shown. It had shown 2 or 3 different codes. I'm pretty certain one was 21, and that's ignition signal. When I tried again, all I got was 34, and that's detonation sensor.

Any ideas off this?

[boost_boy]

I pulled the codes, and I initially missed the first set that were shown. It had shown 2 or 3 different codes. I'm pretty certain one was 21, and that's ignition signal. When I tried again, all I got was 34, and that's detonation sensor.

Any ideas off this?

Is your sensor hooked-up correctly or even at all? I called it charging issues because not only the battery benefits from a properly functioning charging. And as stated from others, if your original idle is (let's say 800rpm) with accesories off, by the time you turn on those accessories, your rpms will drop because of the load.

Dee

[Katapl]

Is your sensor hooked-up correctly or even at all? I called it charging issues because not only the battery benefits from a properly functioning charging. And as stated from others, if your original idle is (let's say 800rpm) with accesories off, by the time you turn on those accessories, your rpms will drop because of the load.

Dee

Well, like I had mentioned... it's all hooked up except the part I circled below.



That piece is unhooked and showing two prongs for a connector.

[ca18detgabby]

Well, like I had mentioned... it's all hooked up except the part I circled below.



That piece is unhooked and showing two prongs for a connector.

that is your idle up for when you engauge your AC

[Katapl]

That's exactly what I thought it was. It's pretty much why I haven't stressed over it until now.

Hmm. It seems like everything else is hooked up. This is pretty odd.

[Katapl]

Could I just pull the battery cable off with the engine running to check and see if the alternator is doing it's job or not? I know that works on older V8's, but I hear it can short out your ignition system... depending on what type of setup you have.

Should I give that a go or not?

[maik21]

i say no, dont do it, alternator need a reference voltaje. if u took off ur battery, the reference will not be there, so voltaje will rise and will damage things.

[Katapl]

By the way, this problem is progressively becoming worse. Now it seems if I'm just sitting in the car with the fan on, it drops if it sits for longer than 5'ish seconds.

The only ECU code I got was knock sensor.

[maik21]

By the way, this problem is progressively becoming worse. Now it seems if I'm just sitting in the car with the fan on, it drops if it sits for longer than 5'ish seconds.

The only ECU code I got was knock sensor.

in 1996, my father had a nissan luccino with 2.0 sr20de... and it has a similar problem u have. the code in ecu was knock sensor and it shows because engine mounts were damaged.... so he replace them and problem was solved.

[Katapl]

Was it a similar idle issue? It just doesn't seem right that the idle would drop because of an engine mounts. Though, yes, the engine mounts are kinda tore-up on this thing.

If it was simply a mount, I'd order a good set of NISMO ones have this thing done.

[maik21]

Was it a similar idle issue? It just doesn't seem right that the idle would drop because of an engine mounts. Though, yes, the engine mounts are kinda tore-up on this thing.

If it was simply a mount, I'd order a good set of NISMO ones have this thing done.

im not lying.. the mechanic told to my father , car need new mounts because knock sensor was shown in the ecu code error. so they put new mounts on it and problem was solved... i dont try to say u need to put new mounts.. its only a 1 more way to solve ur problem.

if mounts are damaged, when engine idle is a little bad, things become worse because bad mounts so idle becomes worse. its what mechanic told to my father.

[Katapl]

Okay, someone reputable just put a multimeter to the alternator, and it tested bad. Apparently, the voltage kept dropping and dropping while accessories were on. I don't know how these other places tested it, but it's definitely not putting out enough to keep everything up.

It could be a bad regulator. That would explain why sometimes it runs good, and sometimes it runs poor.

[maik21]

Okay, someone reputable just put a multimeter to the alternator, and it tested bad. Apparently, the voltage kept dropping and dropping while accessories were on. I don't know how these other places tested it, but it's definitely not putting out enough to keep everything up.

It could be a bad regulator. That would explain why sometimes it runs good, and sometimes it runs poor.

oks.... if its ur alternator... with all accesories off and engine on, u will see a 14+ v in the battery. if ur voltaje is 13.5 or 13.8, u will need to charge first ur battery and then check again voltaje... if battery is fully charged and voltaje its 13-13.8 then u have a bad adjusted belt . u will need to torque it again.

ur idle fails because all amperaje from ur alternator is used to charge ur battery and when u turn accesories on, the battery isnt charged and voltaje drops and then ur spark drops too !!... i recently had this problem in my v8... i torque all days the alternator belt because when i put accesories on , voltaje drops to 13.2-13.5 volts and with sound system on, its was 12.5... my alternator stops while my engine was running and i fried alternator belt. when i rev to 2000 it revs right but when i past from 2000 rpm or up, the engine shake a little.

i tell u that stuff about engine mounts because u say ur charge system was right.

remember, first fully charge ur batteries, then check again !!!

2 fans can eat easily 60amps, plus 13amps from ur headlights (2+55w), plus ur electrical system. ..... maybe 90-100amps ...

[biosehnsucht]

take it to a reputable rebuild shop. shouldn't be more than 80-120ish